Comment 17 for bug 1345433

This happens to me also. Let me clarify things a little bit. From my point of view:

When you are provisioning a server with MAAS it expect all networks go physical. But in my case I have to deploy servers to an openstack network as compute nodes. So I have to bridge all interfaces with openvswitch. This is my choice, and I did this way.

ovs-vsctl show
8d08d8e4-49f2-4243-b1db-7641984a8530
    Bridge br-ex
        Port br-ex
            Interface br-ex
                type: internal
        Port phy-br-ex
            Interface phy-br-ex
    Bridge "br0"
        Port "br0"
            Interface "br0"
                type: internal
        Port "phy-br0"
            Interface "phy-br0"
    Bridge br-ext
        Port br-ext
            Interface br-ext
                type: internal
    Bridge br-int
        fail_mode: secure
        Port "int-br0"
            Interface "int-br0"
        Port "qvoea759488-64"
            tag: 1
            Interface "qvoea759488-64"
        Port "qvod1b2e6dc-7f"
            tag: 1
            Interface "qvod1b2e6dc-7f"
        Port "eth1"
            Interface "eth1"
        Port br-int
            Interface br-int
                type: internal
        Port int-br-ex
            Interface int-br-ex
        Port "qvoc0571326-4c"
            tag: 1
            Interface "qvoc0571326-4c"
    ovs_version: "2.0.2"

In my case br-int communicates with the internal integration network. Where MAAS is available for me.

br-int Link encap:Ethernet direcciónHW 68:05:ca:1a:09:50
          Direc. inet:172.16.0.100 Difus.:172.16.31.255 Másc:255.255.0.0
          Dirección inet6: fe80::e46e:23ff:fe3c:c279/64 Alcance:Enlace
          ACTIVO DIFUSIÓN FUNCIONANDO MTU:1500 Métrica:1
          Paquetes RX:577447 errores:0 perdidos:0 overruns:0 frame:0
          Paquetes TX:724745 errores:0 perdidos:0 overruns:0 carrier:0
          colisiones:0 long.colaTX:0
          Bytes RX:3114547329 (3.1 GB) TX bytes:908737979 (908.7 MB)

MAAS is 172.16.0.40.

What I think it happens is that ubuntu brings up all interfaces but openvswitch. Then it tries to see if network is up, but it's not because the bridges and rest of the config is not done. OpenVSwitch config is still not started. So it waits for network interfaces. And finally fails.

After a while of waiting, it starts the openvswitch stuff and brings the net up. But cloud-init already failed. In my case is worse even because I depend on ceph and ceph is started even after of openvswitch so it also fails, and starts failed. No more recover. So I have to do it manually after it boots.

I think solution is to bring openvswitch config with the rest of the system. I rode about it but it seems that I cannot set configuration it /etc/network/interfaces since it does not work. So I'm sticking with ovsdb config.

What do you think? Can this be the problem?